An ink jet printer typically includes a printhead and a carrier. The ink jet printhead can comprise a printhead body, nozzles, and corresponding ink ejection actuators, such as heaters on a printhead chip. The actuators cause ink to be ejected from the nozzles onto a print medium at selected ink dot locations within an image area. The carrier moves the printhead relative to the medium, while the ink dots are jetted onto selected pixel locations, such as by heating the ink at the nozzles.
In some such systems, the ink reservoir comprises a removable or separable tank, such that the tank can be separated from the printhead, and replaced or refilled, when the ink is low. The printhead components can then be re-used. In such ink tank systems, a separable fluid connection between the tank and the printhead body is needed, in contrast to systems where the printhead body is integral with the ink reservoir. The connection permits ink to flow to the nozzles from the tank, but is separable such that the ink tank can be removed when empty.
The printhead assembly can also include a filter within an ink passageway leading from the ink reservoir to the nozzles, for isolating any contaminants or debris from the ejectors and nozzles. The filter is typically swaged onto a tower or passage leading to the nozzles. However, when the tank is installed in this manner, the filter edges can rub against the tank entrance, thereby abrading the raw filter edges and creating the possibility that the filter becomes damaged, and allowing loose particles to reach the nozzles and create clogging issues.
In some manufacturing techniques, the sides of the filter are swaged onto the tower, and the filter edges are encapsulated in plastic. However, such a process can require tight tolerances for precise placement of the filter that are difficult to achieve and require significant manufacturing time. Swaging also can place cut edges of the filter inside a pocket during the swage operation, and in a position for any particles that shed from the filter edge to be pushed under the filter. Particles from the edges can then travel to the chip and clog the nozzles on the chip.
In addition, some designs do not protect the filter when the tank is removed, such that ink on the filter can dry out, or the filter can otherwise be damaged, prior to the installation of the replacement tank. The dried ink can permanently clog the filter and ruin the printhead.
Accordingly, improved ink tank connections, printhead filter systems and methods of manufacturing the same are desired.